How to make a file "non local-specific" for sheep-it render farm?
This just means that you need to make all file paths relative, instead of absolute. If you understand what that means, that's great. If not, I'll provide some explanation below (I don't intend to be insulting, if you already understand).

Relative and absolute paths are a bit beyond the scope of this site, but I can give a brief explanation.

If you have a Blender file that uses an image texture which is located at H:\Users\Node's Stuff\Blender Awesomeness\Sweet_Render\ReadyForSheepIt\Textures\FinalGroundTexture.png then Sheep-It won't know where to find it, because no such folder exists on their server.

That is called an "absolute path." No matter where you are on the machine, that path gives you everything you need to know in order to find FinalGroundTexture.png.

Alternatively, you can say "I don't care what hard drive you're on, and I don't care what higher folder you're in, just look in the folder next-door." This would be a relative path. If you had a Blender file in ReadyForSheepIt you could tell the Blender file that the texture is in \Textures\FinalGroundTexture.png. In this way, you tell Blender that it doesn't matter where the Blend file is located, it can find the texture by looking in whatever folder the Blend file is currently in, and finding a folder called Textures.

Regardless, there is a tool in Blender that will do a lot of the work for you.

From the Manual:


  If it is necessary to relocate a blend-file relative to its linked resources, use Blender’s File Save As function which has an option to Remap Relative file links.


You can just "Save As..." without changing the file name, and that'll give you the chance to "Remap Relative" to make sure you don't have any absolute paths.